1. Field of the Invention
The present invention relates generally to cameras for taking a plurality of exposures on a continuous length of film and, more particlarly, to a camera used primarily in slide production, slide reproduction, slide animation, and movie animation applications.
2. Description of the Prior Art
Cameras of the type used for commercial slide production, slide reproduction, slide animation and movie animation are well known in the art of photographic equipment. When used for slide production or animation applications, such cameras are often required to expose a particular frame of film more than once. In some applications, each frame of film may be exposed as many as ten to twenty times. Multiple exposures of a particular frame of film serve to superimpose two or more different images upon each other.
As an example, a first subject, such as a cartoon character, is photographed repeatedly on successive frames of film. Following the exposure of the film to the first subject, the film is reversed back to the initial frame, and a second subject, such as background against which the cartoon character is to appear, is again photographed repeatedly on the same successive frames of film which were initially used to record the image of the cartoon character. The cartoon character thus appears superimposed against the background within each frame of film.
To properly compose a multiple exposure photograph, it is highly advantageous to be able to view an image of the subject next to be photographed on a frame of film superposed with the image or images already recorded on that frame of film. When thus viewed, the subject next to be photographed can be positioned such that its image is properly aligned with respect to the image or images already recorded on the frame of film. A well-known method of achieving such a superposition of the images, prior to actually exposing the film to the subject next to be photographed, involves removing from the camera a portion of the film which has already been exposed to the previously photographed subject or subjects. The portion of film removed from the camera is then developed to render the recorded image or images visible. Cameras of the type described above typically include a ground glass reticle for allowing the camera operator to view an image of the subject next to be photographed. Therefore, if the developed portion of film is positioned behind the ground glass reticle, then the image of the subject next to be photographed and the image or images previously recorded on the developed portion of film will be simultaneously projected onto the ground glass reticle. The camera operator may then observe the superposed images displayed by the ground glass reticle while repositioning the subject next to be photographed in order to properly compose the multiple exposure photograph.
In the past, users of such cameras have been known to remove the ground glass reticle from the camera and to affix a film chip containing the developed portion of the film to the back side of the ground glass reticle with adhesive tape. The ground glass reticle is then reattached to the camera to permit simultaneous viewing of the images previously recorded and the image of the subject next to be photographed. However, the operations of removing and subsequently reattaching the ground glass reticle, in order to prepare for each new exposure, are burdensome and time consuming. In addition, when the film chip is to be attached to the ground glass reticle, the film chip must be manipulated until it is properly aligned with the reference markings on the ground glass reticle prior to application of the adhesive tape in order to accurately represent the image already recorded upon the frame to be re-exposed.
Accordingly, it is an object of the present invention to provide a camera for taking a plurality of exposures upon a continuous length of film, the camera permitting a user to position a previously developed film strip behind a ground glass reticle for superposing an image to be photographed with an image previously recorded on the film strip without requiring that the ground glass reticle be removed from the camera and subsequently be reattached to the camera.
A further object of the present invention is to provide such a camera wherein a previously developed film strip can be properly aligned with respect to the ground glass reticle without requiring extensive manipulation of the film strip.
A yet further object of the present invention is to provide such a camera wherein a film strip can be positioned behind a ground glass reticle without requiring the application of adhesive tape or other such means.
As described above, cameras of the type used for slide production, slide animation, and movie animation are often used to expose a particular frame of film several times in order to superpose different images upon the same frame of film. If the images to be superposed will be positioned on separate portions of the frame of film, then it may be necessary to prevent the light received by the camera lens while photographing a first image from exposing the portion of the frame of film which will be exposed to the second image, and vice versa.
Additionally, users of such cameras may desire to vary the size of the exposed frame of film, particularly when switching between different frame formats (e.g., 35 mm. film strip and 35 mm. full frame).
Accordingly, it is an object of the present invention to provide a camera for taking a plurality of exposures upon a continuous length of film, the camera including a mechanism for quickly and conveniently varying the area of film to be exposed without requiring disassembly of the camera, removal of the film from the camera, or opening the front of the camera.
It is another object of the present invention to provide such a camera having a mechanism for conveniently and selectively exposing different portions of a particular frame of film without requiring disassembly of the camera, removal of the film from the camera, or opening the front of the camera.
It is another object of the present invention to provide such a camera adapted to superpose two or more different images upon a single frame of film.
It is another object of the present invention to provide such a camera which allows the camera user to mask out portions of a frame of film during an exposure cycle according to any masking pattern desired by the user.